cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A075585 Primes p such that the number of distinct prime divisors of all composite numbers between p and the next prime is 5.

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%I A075585 #16 Sep 08 2022 08:45:07
%S A075585 19,23,37,43,97,127,223,499,673,1213,2309,2729,6089,6269,7589,8969,
%T A075585 9239,9281,10709,11549,11969,12539,13397,14321,15329,16829,17489,
%U A075585 18059,19139,19379,19469,19889,20747,21317,21839,22109,22619,23369,23561,24179
%N A075585 Primes p such that the number of distinct prime divisors of all composite numbers between p and the next prime is 5.
%H A075585 Amiram Eldar, <a href="/A075585/b075585.txt">Table of n, a(n) for n = 1..10000</a>
%t A075585 dpd5Q[p_]:=Length[Union[Flatten[FactorInteger[#][[All,1]]&/@Range[ p+1,NextPrime[ p]-1]]]]==5; Select[Prime[Range[3000]],dpd5Q] (* _Harvey P. Dale_, Aug 11 2021 *)
%o A075585 (Magma) a:=[]; for k in PrimesInInterval(2,25000) do b:={}; for s in [k..NextPrime(k)-1] do if not IsPrime(s) then b:=b join Set(PrimeDivisors(s)); end if; end for; if #Set(b) eq 5 then  Append(~a,k); end if; end for; a; // _Marius A. Burtea_, Sep 26 2019
%Y A075585 Cf. A052297, A075581, A075580, A059960, A075583, A075584, A075586, A075587, A075588, A075589.
%K A075585 nonn
%O A075585 1,1
%A A075585 _Amarnath Murthy_, Sep 26 2002
%E A075585 More terms from _Sam Alexander_, Oct 21 2003